Developments in unmanned powered parachute aerial vehicle: A review

The U.S. Department of Defense (DOD) defines an unmanned aircraft as the following: A powered vehicle that does not carry a human operator, can be operated remotely or autonomously, can be expendable or recoverable and can carry a lethal or non-lethal payload. Ballistic or semi ballistic vehicle, cruise missiles, artillery projectiles, torpedoes, mines, satellites and unattended sensors are not considered unmanned vehicles. Unmanned vehicles are the primary component of an unmanned system [1].